Thirty years after a prominent Montreal psychiatrist performed a series of mind-control experiments on patients -- including giving them heavy doses of LSD -- seven of the former subjects yesterday reached a tentative settlement for damages with the CIA for its part in funding the doctor and his treatments.

Sources said the former patients would receive a total of $750,000 if the settlement is approved by the Department of Justice. The sources said it is one of the largest amounts the Central Intelligence Agency has ever agreed to pay resulting from civil litigation.

U.S. District Judge John Garrett Penn set a hearing this morning to review the proposed settlement.

The tentative accord came on the eve of a civil trial that had been scheduled to begin today in federal court. The case was expected to dwell on what some CIA critics call one of the most shameful episodes in the agency's history: its involvement in the psychiatric practice of Dr. D. Ewen Cameron in the late 1950s.

Cameron, who died in 1967, was a Scottish-born American who practiced at the Allan Memorial Institute of McGill University in Montreal. From 1957 to 1961, he treated more than 50 patients who sought help for various psychological ailments, such as depression and anxiety.

His goal was to reprogram behavior, and his methods caught the interest of CIA officials at the height of the Cold War. At the time, the intelligence agency was concerned with countering purported Soviet and Chinese breakthroughs in brainwashing and interrogation.

In their day, Cameron's techniques were unusual; today they sound harrowing.

To break or "depattern" habits and personality traits, Cameron subjected his patients to drug-induced "sleep therapy" for weeks at a time, gave them LSD and administered electroshock therapy at up to 75 times the usual intensity. At the same time, Cameron sought to impel new behavior by having his patients listen to recorded messages, played continuously for days at a time -- a practice known as "psychic driving."

"He was inducing organic brain syndromes, damaging the central nervous system, reducing people to a zombielike state," said James C. Turner, the attorney for the seven former patients and one widower of a patient who are suing the government. "These are really horrific kinds of procedures, and the combination is unheard of."

Government lawyers have disputed that point. In pleadings filed in federal court here, they argue that Cameron's techniques, although controversial, were not outside the bounds of accepted psychiatric practice in the late 1950s.

Cameron, they stress, was one of the world's preeminent psychiatrists, a widely published scholar who was elected president of the American Psychiatric Association and the Canadian Psychiatric Association. Both before and after Cameron received $59,467 from a front organization funded by the CIA, he was awarded grants for his research from the Canadian government.

Cameron's "investigations were not dictated or controlled by the CIA in any way and there is no evidence that {he} was ever aware that the CIA was the source of his funding," the government said. "Dr. Cameron was a well meaning and well motivated doctor who genuinely hoped he could relieve some of his patients' suffering."

Nearly all the former patients now suing the government are elderly, and all say their lives were impaired by Cameron's treatment.

In a 1985 interview with The Washington Post, Velma Orlikow described what she said was the legacy of her treatment by Cameron, which included 14 shots of LSD as well as psychic driving.

"I suffer from chronic depression which sometimes becomes acute," said Orlikow, the wife of a Canadian member of Parliament. "I call these periods my black holes. I don't see anybody and I won't leave the house. I can't read and I used to love to read. I can't write a letter. I have unexplained fears. I wake up at night afraid and I don't know why. I'm trying to limp through my life like someone who's been in a terrible accident that leaves them crippled."

Orlikow and the other plaintiffs say they never consented to the specific treatments they received, nor were they told their cases were being used for research.

The government said that Cameron's actions must be considered in their historical context: in the late 1950s, government lawyers contended in court papers, "the doctrine of informed consent, as it is now understood, did not exist." By having his patients sign a general consent form that did not specify treatments and methods, Cameron was following the dictates of medical ethics as they existed in Canada and the United States at the time, the government contended.

The government further argued that there is no evidence that Cameron's patients were injured by the treatment they received. In any event, government lawyers said, the CIA should not be found negligent because Cameron's program was under way before the CIA channeled money to him and after the funding stopped.

Cameron was like an independent contractor, government lawyers argued: His actions were not guided or controlled by the CIA, and his decisions on treating patients were discretionary. As such, the government argued, they are not open to lawsuits under the Federal Tort Claims Act. But the former patients said the CIA should have known that the experiments were dangerous.

They cited the now-notorious case of Dr. Frank Olson, an Army scientist whose after-dinner liqueur was secretly spiked with LSD by CIA agents in 1953 as part of the agency's brainwashing research program. That night Olson jumped to his death from a 10th-floor hotel room.

The incident prompted an internal investigation at the CIA, and more than 20 years later, President Ford apologized for Olson's death and signed legislation providing $750,000 to his survivors.

Alice W. Olson, the scientist's widow, was scheduled to be the first witness for the plaintiffs in the trial that was to have started today.

The former patients said it was the agency's responsibility to oversee Cameron's experiments, particularly because they entailed the use of LSD. The CIA's failure to do so, they say, amounts to negligence.

"The case is about whether an agency of this government should have allowed this thing to go forward when it was so destructive to people," said Leonard S. Rubenstein, legal director of the Mental Health Law Project and an attorney for the former patients.

"The only real question . . . is the CIA's legal guilt," said veteran civil rights lawyer Joseph Rauh Jr., who handled the case until his retirement two years ago. "Their moral guilt is already admitted."

Dr. D. Ewen Cameron used these methods to break or "depattern" habits and personality traits:

Used drug-induced "sleep therapy" for weeks at a time.

Administered LSD and electroshock therapy at up to 75 times the usual intensity.

Had patients listen to recorded messages, played continuously for days at a time -- a practice known as "psychic driving."